Respiratory apparatus



June 1970 M. F. FRAEEMAN 3,515,

RESPIRATORY APPARATUS Filed Feb. 26, 1968 INVENTOR Mnumce F. FREEMAN JQLILTJI'LMY ATTORNE Y United States Patent 3,515,163 RESPIRATORY APPARATUS Maurice IYederlck Freeman, Cumnor Hill, Oxford, England, assignor to H. G. East & Company Limited, Oxford, England, a British company Filed Feb. 26, 1968, Ser. No. 708,139 Claims priority, application Great Britain, Mar. 14, 1967, 11,857/67 Int. Cl. A61m 16/00; G05b 7/00; F16k /02 US. Cl. 137-102 7 Claims ABSTRACT OF TIIE DISCLOSURE Respiratory apparatus comprising a non-rebreathing valve capable of regulating the breathing of a patient during medical treatment where air or other gas to be administered to the patient is pressurised for forced ventilation. The valve comprises a valve body containing a control valve member movable either to close an exhaust valve and simultaneously permit communication between an inlet and an outlet to the patient or to close the inlet and simultaneously allow communication between the outlet to the patient and the exhaust outlet. A manually adjustable device controls a biasing force which tends to urge the control valve to close the inlet. When the pressurised air or other gas fed to the inlet causes the control valve member to move to open such inlet the inlet gas pressure is applied also to the outlet side of the control valve so that the control valve is then substantially entirely under control of the biasing force.

in respiratory apparatus for medical treatment and for the administration of anaesthetics it is a common practice, when spontaneous respiration is not possible, to maintain breathing in a patient by forced ventilation, i.e. blowing air under suitable pressure, or other gases e.g. froman anaesthetic apparatus, intermittently into the lungs. Expiration from the lungs occurs when the pressure is released and placing the lungs in communication with the atmosphere. A pressure-responsive control valve is pro vided to regulate the breathing operation, the valve comprising a valve body having an inlet for air or gas to be administered to a patient and an outlet for the air or gas connectible with the patient and a freely movable valve biased to a position to shut-oil the inlet from the outlet, the valve being moved to interconnect the inlet and the outlet upon the application of a suitable pressure at the inlet. Such a valve is provided to ensure that air or gases expired by the patient-is or are not mixed with the air or gases subsequently inspired by the patient. Accordingly such a valve is commonly referred to in the present specification and claims as a non-rebreathing valve.

According to one aspect of the invention there is provided respiratory apparatus comprising a non-rebreath ing valve capable of regulating the breathing of a patient during medical treatment where air or other gas to be administered to the patient is pressurised for forced ventilation, the valve including a valve body having an inlet for such air or other gas, an outlet for said air or other gas connectible with the patient, an exhaust outlet from the body for gases exhaled by the patient, a control valve movable either to close the exhaust outlet and simultaneously permit communication between the inlet and outlet to the patient or to close the inlet and simultaneously allow communication between the outlet to the patient and the exhaust outlet. means applying a biasing force to said control valve to urge same to close the inlet, and a manually aetuable device to adjust such biasing means so as to vary the force urging the control valve to close the inlet, the arrangement being such that when the pressur- Patented June 2, 1970 The control valve may be movable between the inlet and the outlet to the patient.

The valve body may comprise a generally tubular member with the inlet comprised by one open end of the tubular member and the outlet to the patient comprised by the other open end of the tubular member.

The body may be formed with an inwardly directed flange at a central portion thereof and the control valve may be of generally tubular configuration and a sliding, substantially gas-tight fit, with the central portion of the body, the control valve having an end plate at 'its end toward the inlet which isformed with an axially directed flange which abuts said inwardly directed flange of the body in substantially gas-tight manner when the control valve is in a position to close the inlet.

The end plate of the control valve may be formed with at least one aperture radially outwardly with respect to the axially directed flange, whereby the air or other gas can flow therethrough and through the control valve to the outlet to the patient when the control valve is in its position such that the inlet is open.

The exhaust outlet may comprise an opening in said tubular member intermediate the ends thereof.

The tubular external surface of the control valve may be formed with at least two radially extending flanges which slidably mount the control valve in the body, the body being formed with an opening which comprises said exhaust outlet, positioned at said central portion of the body between the outlet to the patient and the part of the central portion engaged by the radially extending flanges on the control valve.

The exhaust outlet may comprise a generally tubular portion which extends normal to the tubular member and communicates with an annular air space which is present around the whole of the tubular member, the control valve abutting a valve seat in the body, with its end remote from the end plate, to prevent communication between the annular air space and the inside of the body when the inlet is open.

Said biasing means may comprise magnetic means. Said magnetic means may comprise a permanent magnet carried by said control valve and a further permanent magnet carried by said manually aetuable device so as to be adiustable towards and away from said permanent magnet.

The valve body may comprise a metal casting and the valve body and the control valve may be fabricated of an aluminium alloy. The manually adjustable means may. also be fabricated of the same aluminium alloy.

The foregoing and further features of the invention may be. more readily understood from the following description of a preferred embodiment thereof, by way of example, with reference to the accompanying drawing, in which:

FIG. I is a side sectional view of a non-rebrcathing valve with the control valve thereof positioned such that the inlet is in communication with the outlet to the patient, and

FIG. 2 is a side sectional view of the valve of FIG. I with the control valve in the position such that the outlet to the patient is in communication with the exhaust out- 7 let.

such as Duralumin or is fabricated of a plastic material.

The valve body 10 comprises a'generally tubular member,

of which one open end comprises an inlet 11 and the other open end comprises an outlet 12 which is for connection to a patient. A central portion 13 of the valve body carries an axially slidabie control valve member 14 therein and is formed with a further generally tubular member 115, the free end 16 of which comprises the exhaust out- An inwardly directed flange 17 is provided toward the end of the central portion 13 of body which is adjacent inlet 11. the flange 17 producing a reduced diameter aperture 18 for the flow of air or other gas through the valve body from the inlet 11.

The central portion 13 of the body 10 is formed with an annular air space 19 which is in communication with the exhaust outlet 16 at the side of the body 10 where the tubular member is provided. The annular air space 19 communicates with the space inside the body 10, when the control valve member 14 is in its position to close the inlet (FIG. 2), via an annular slot 20 formed in the body 10. The body 10 is formed with an annular bevelled portion 21 at the end of the central portion 13 adjacent the outlet 12 so as to aid flow during expiration of the patient. A radially extending flat face 21' is provided inwardly of portion 21 so as to provide a valve seat.

The control valve member 14 may also be a mctal'casting and preferably is of the same aluminium alloy as that used for fabricating the body member 10 e.g. Duralumin. Alternatively the control valve member 14 may be fabricated of a plastics material. The body member 14 comprises a tubular portion 22 formed with two radially extending flanges 23 from its outer surface which slidably engage the inner surface of the central portion 13 of body 10. The flange 23 provide a substantially gas-tight joint between valve control member 14 and the inner surface of valve body 10 and are preferably arcuate at their outer edges e.g. with a radius of between and M The end of the control valve member 14 which lies toward the inlet 11 is formed with an end plate 23 carrying a central ferrule 24 in which is mounted a permanent magnet 25 which forms a part of a magnetic biasing arrangement. An axially directed flange or rim 26 is formed on the outer surface of the end plate 23 so as to engage the flange 17 when the control valve member 14 is in position to close the inlet; i.e. FIG. 2. A number of holes 27 are formed through the end plate 23 radially outwardly with respect to the flange or rim 26. The end of the valve control member 14 remote from the end plate 23 is open and preferably has its end surface 28 rounded so as to provide a gas-tight seal with the face 21' of the body 10 when the valve control member 14 is in its position to open the inlet and close the exhaust outlet, i.e. P10. 1.

The magnetic biasing means comprises, in addition to the permanent magnet 25 a further permanent magnet 29 which is oppositely poled compared with the permanent magnet 25 and carried by a manually adiustable device 30. The manually adjustable device 30 comprises a plug 31 which is slidable wtihin the inlet 11, has an aperture 32 formed therethrough the carries the permanent magnet 29. A sleeve 33 which is: close sliding lit with the outer surface of the body 10 at the inlet end 11 is connected to the plug 31 by a screw 34. The sleeve 33 and plug 31 may be fabricated of aluminium alloy or as plastics material. The screw 34 passes through the body member 10 at an aperture 35 which is in the form of a part of a helix so as to provide a portion'of a turn of a coarse screw thread such that partial rotation of the sleeve 33 causes axial movement of the permanent magnet 29 towards or away from the permanent magnet 25 carried by the conconnected to the patient requiring nnncsthctising and/or forced respiration. The cycle of events commences with the control valve member 14 in its position shown in FIG. 2. i.e. with the inlet closed. When the reservoir bag is inflated to a sufficient pressure to overcome the force of magnetic attraction between the permanent magnets 25 and 29 the control valve member 14 is moved to the right as shown in the figures so as to assume the position shown in FiG. 1. The air or other gas passes through the inlet opening 11 to the outlet 12 to the patient along the path denoted by the arrows 36 in FIG. 1. it will be seen from these arrows that the path comprises inlet opening 11. aperture 32in plug 31. aperture 18 defined by flange 17. the inside of valve member 10, aperture 27 in end plate 23 of valve member 14. the inside of the tubular member 22 of valve member 14 to the outlet 12 to the patient. it should be noted that as the control valve member 14 moves to the right allowing the air or other gas to pass through the aperture 18 it passes almost immediately through the apertures 27 so that the pressure on each side of end plate 23 of control valve member 14 is quickly equalised as the patient becomes inflated. Thus control valve member 14 is returned to the control of the biasing means and relatively quickly is moved to the left so as to close the inlet as illustrated by FIG. 2. The patient exhales at this point and the air and/or other gases pass through the non-rebreathing valve in the direction of the arrows 37 on FIG. 2. it will be seen that these gases enter the outlet 12 from the patient and pass through the slot 20 and annular air space 19 to the exhaust outlet 16. When the pressure has again built up in'the reservoir bag suflicient to overcome the force of the magnetic attraction of the permanent magnets 25 and 29 the control valve member 14 again moves to the right so as to assume the position of FIG. I. The path for air and/or other gases is the same as previously described and it should be further noted that the control valve member 14 in moving to the right closes the slot 20 by the rim 28 engaging the annular bevel 21 so that the path from the exhaust outlet 16 to the outlet 12 is closed.

Upon opening of the inlet 11 the air or gas pressure on the control valve 14 acts in opposite directions and the pressure at the patient quickly approaches the pressure supply so that the forces are balanced and the control valve member 14 is substantially entirely under the influence of the magnetic biasing arrangement. Closing of the inlet 11 is assured with greater accuracy and certainty. The application of the air or gas pressure to the outlet side of the control valve 14 is performed internally of the control valve member 14 and automatically upon opening of the inlet so that a non-rcbreathing valve of simple and relatively cheap construction free of external excrescences is provided.

I claim:

1. Respiratory apparatus comprising a nonrcbreathing valve for regulating the breathing of a patient during medical treatment where air or other gas to be administered to the patient is pressurised for forced ventilation.

I said valve comprising:

trol valve member 14. Either one of the permanent magnets may be replaced by a magnetic, ferrous member but in any event magnetic attraction is provided between the members 23 and 29.

in operation the inlet opening 11 is connected to a suitable and preferably flexible conduit from the reservoir bag of a normal anaethetic equipment. The outlet 12 is a valve body including: 7 I

a generally tubular member, one end of said tubular member comprising an inlet for said air or other gas, and the other end of said tubular member comprising an outlet for said air or other gas connectible with the patient;

an exhaust outlet fromsaid valve body for gases exhaled by the patient; and

an inwardly directed flange formed at a central portion ofsaid tubular member;

a movable control valve member of generally tubular configuration forming a sliding, substantially gastight, fit within a central portion of said tubular member for selectively closing said exhaust outlet and simultaneously permitting communication between said'inlet and said outlet to the patient, and

closing said inlet and simultaneously allowing communication between said outlet and said exhaust outlet, said control valve member having an end plate at the end thereof towards the inlet, said end plate having an axially directed flange formed thereon which abuts said inwardly directed flange of said tubular member in substantially gas-tight manner when said control valve is in a position to close said inlet;

biasing means applying a force to said control valve member to urge same to close the inlet; and

a manually actuable device coupled to said biasing means to vary the force urging said control valve member to close the inlet, so that when said prcssurized air or other gas is fed to said inlet the control valve is caused to move to open said inlet and to apply said gas pressure also to said outlet side of said control valve member, the control valve member then being substantially entirely under control of said biasing force.

2. Apparatus as claimed in claim 1 wherein the end plate of the control valve is formed with at least one aperture radially outwardly with respect to the axially directed flange, so that the air or other gas can flow therethrough and through the control valve to the outlet to the patient when the control valve is in its position such that the inlet is open.

3. Apparatus as claimed in claim 1 wherein the exhaust outlet comprises an opening in said tubular member intermediate the ends thereof.

4. Apparatus as claimed in claim 1 wherein the tubular external surface of the control valve is formed with at least two radially extending flanges which slidably mount the control valve in said valve body. the body being formed with an opening which comprises said exhaust outlet, positioned at said central portion of the body 6 between the outlet to the patient and the part of he central portion engaged by the radially extending flanges on the control valve.

5. Apparatus as claimed in claim 4 wherein the exhaust outlet comprises a generally tubular portion which extends normal to the tubular member; said valve body has an annular air space formed therein around the whole of the tubular member, said air space communicating with said exhaust outlet; a valve seat being formed in the body against which the control valve abuts with its end remote from the end plate, to prevent communication between the annular air space and the inside of the body when the inlet is open.

6. Apparatus as claimed in claim 1 wherein said biasing means comprises a first permanent magnet carried by said control valve and a further permanent magnet carried by said manually actuable device so as to be adjustable towards and away from said first permanent magnet.

7. Apparatus as claimed in clim 6 wherein either said first permanent magnet or said further permanent magnet is replaced by a magnet sensitive ferous member.

References Cited UNITED STATES PATENTS 2,876,785 3/1959 Huxley.

2,990,838 7/1961 Cross l37-102 3,265,062 8/1966 Hesse 25i65 3,360,007 12/1967 Haidek 128-1455 WILLIAM F. ODEA, Primary Examiner W; H. WRIGHT, Assistant Examiner US. Cl. X.R'. l3763; 251-65 

